This application claims priority from Japanese Patent Application Reference No. P00-115782, filed Apr. 11, 2000.
The present invention relates to a computer system with databases. More specifically, the present invention relates to the replication of databases in a computer system in which different types of database management systems (DBMS) are present.
In the past, corporate information systems comprised mainly of on-line transaction processing systems (OLTP systems) that primarily used mainframes. These are known as enterprise systems or management systems. However, in recent years OLTP systems by themselves could not provide efficient support for strategic decision making, and this has led to the introduction of data warehousing. In data warehousing, history information is extracted and accumulated over time from OLTP systems to allow efficient analysis of client trends and market trends. This type of system is also referred to as an integrated information system.
While conventional OLTP systems have been built primarily around mainframes, data warehouses and data marts are often built with open systems. Thus, platforms and performance requirements may vary, and the DBMS used in the OLTP system is often different from the DBMSs used in the data warehouses and data marts. Thus, in today""s corporate information systems, different DBMSs are used together, and data must be extracted and updated between these databases.
However, analyzing client trends and markets brings the need for the most recent data that will allow the most appropriate services and products to be provided and will allow the most effective investment decisions. Furthermore, a composite analysis of different types of information is likely to allow more effective analysis. However, there is generally a trade-off between the amount of data to be extracted and the frequency at which data is to be extracted, and there is a limit to how much both can be increased. Without appropriate control over performance, optimal analysis cannot be provided.
What is really needed are techniques for combining databases, especially databases having heterogeneous formats, in a disk storage system.
According to the invention, techniques for combining databases, especially databases having heterogeneous formats, by creating an intermediate copy of data in a disk storage system are provided. Such techniques can be embodied in methods, computer software and the like, that can be disposed on a server, for example, within a computer system. The present invention can provide embodiments that perform data replication by creating an intermediate file in a disk storage system. Embodiments according to the present invention can allow resources of the disk storage system to be managed in a way that meets the requested specifications of the user, and can allow replication to be implemented in a manner that satisfies user specifications such as requested refresh rates.
In a representative embodiment, a refresh manager manages refresh of data to a database, and can receive a requested refresh rate from a user. Further, a performance manager can control information transfer capacity of the disk storage system based on the provided replication information volume and the requested refresh rate. Furthermore, the disk storage system includes a plurality of host interfaces, a plurality of volumes, and modules for allocating volumes that can be accessed from the host interfaces. The disk storage system also includes a module that controls the sharing of volumes among heterogeneous interfaces and controls transfer capacity based on instructions from a module for combining databases, e.g., allocation of volumes and allocation of host paths.
In another representative embodiment according to the present invention, a method for replicating a database is provided. The method is operable in a computer system comprising a disk subsystem, having a plurality of storage volumes, in which the disk subsystem is connected to a plurality of computers by one or more information channels including a network. The method can comprises a variety of steps, such as receiving at a first computer one or more requested specifications relating to replication. A step of determining a data transfer capacity according to the specifications can also be part of the method. The method can also include determining one or more data transfer capacity settings according to the data transfer capacity and notifying the disk subsystem of the data transfer capacity settings. Further, the method can include allocating resources in the disk subsystem for data transfer based on the data transfer capacity settings; and then copying content from a first database to a second database using the resources in the disk subsystem. The copying is performed using the resources in the disk subsystem substantially independently of sending the content over the network.
In a further representative embodiment according to the present invention, in a computer system including a first server and a second server, interconnected by a network to a disk storage subsystem, a method for replicating content of a first database associated with the first server to a second database associated with the second server is provided. The first database and the second database can be disposed in the disk storage subsystem, for example. The method comprises a plurality of steps, including allocating resources to perform a copy within the disk storage subsystem. A step of replicating content from the first database to the second database is also included in the method. The replicating is performed using the resources in the disk subsystem substantially independently of sending the content over the network.
In a specific embodiment, the computer system can also comprise a third server. The method can further include steps such as a step of receiving at the third server one or more requested specifications relating to replication. The method can also include determining a data transfer capacity according to the specifications and determining one or more data transfer capacity settings according to the data transfer capacity. The disk subsystem can be notified of the data transfer capacity settings, and resources can be allocated in the disk subsystem for data transfer based on the data transfer capacity settings.
In a yet further embodiment according to the present invention, a disk storage subsystem is provided. The disk storage subsystem is operable in a computer system comprising a plurality of computers, which can be interconnected to the disk storage subsystem by one or more of information channels, including a network, for example. The disk storage subsystem can copy content from a first database to a second database using resources in the disk subsystem substantially independently of sending the content over the network. The copy is performed by the disk storage subsystem in accordance with a resource allocation received from one of the plurality of computers. The resource allocation based upon one or more of data transfer capacity settings determined by the one of the plurality of computers in accordance with a data transfer capacity and one or more of received specifications.
In a still further embodiment, a computer program product for replicating a database is provided. The computer program product is operable in a computer system comprising a disk subsystem, having a plurality of storage volumes, the disk subsystem connected to a plurality of computers by one or more of information channels, including a network, for example. The computer program product comprises a computer readable storage medium containing a variety of code. For example, the computer program product includes code for receiving at a first computer one or more requested specifications relating to replication. Further, the computer program product can include code for determining a data transfer capacity according to the specifications and code for determining one or more of data transfer capacity settings according to the data transfer capacity. Code for notifying the disk subsystem of the data transfer capacity settings can also be included in the computer program product. The disk subsystem allocates resources for data transfer based on the data transfer capacity settings provided by said code for notifying. Further, the disk subsystem, responsive to the code for notifying, will perform a copy of content from a first database to a second database using the resources in the disk subsystem. This copy is performed using the resources in the disk subsystem substantially independently of sending the content over the network.
Numerous benefits are achieved by way of the present invention over conventional techniques. In a system performing replication by creating an intermediate file in a disk storage system, the present invention allows resources of the disk storage system to be managed in a way that meets the requested specifications of the user, and allows replication to be implemented in a manner that satisfies user specifications such as requested refresh rates. These and other benefits are described throughout the present specification. A further understanding of the nature and advantages of the invention herein may be realized by reference to the remaining portions of the specification and the attached drawings.